In conventional erosion control systems for the protection of sloped surfaces, it has been customary to assemble precast concrete members of straight bar shape into rectangular or triangular frames along the sloped surface to be protected, or to deposit concrete onto reinforcing bars disposed on the sloped surface to be protected, in rectangular or triangular frame configuration so that stones can be placed, or soil can be deposited for the subsequent planting in the open spaces defined by the frames. However, in such conventional installations, difficult and dangerous work has been required, such as the conveying and fixing of heavy materials on sloped surfaces and, thus, the work proceeds slowly and inefficiently.
To overcome the aforementioned shortcomings associated with such conventional erosion control systems, there has been proposed a mat in which one piece of flexible fabric sheet material composed of single-layer portions, and double-layer portions forming bag-like portions disposed in rectangular or triangular shapes, is placed over the sloped surface to be protected and fluid concrete is introduced into the bag portions defined by the double-layer portion of the sheet so as to form a frame. However, in order to provide the sloped surface protected by such a frame means with plantings, e.g. trees, grass, etc., open portions must be provided by removing the single-layer portions or diagonally cutting the single-layer portions so that seeds can be sown or trees can be planted in said open portions. This results in a large amount of fabric material being removed and wasted.
Accordingly, an object of the present invention is to provide a novel erosion control mat of textile material in which the migration of earth and sand is prevented by seeding and planting open areas defined by an integrated arrangement of frame units without removing or cutting fabric portions to create open areas thereby solving the aforementioned shortcomings associated with conventional erosion control mats.